Help!! Engine runs crappy & smokes after valve stem seal replacement.

My K5 was smoking on startup and after reading up on it in the manual, I decided to replace the valve stem seals. I read the factory manual and Chiltons. Since it looked pretty straightforward I decided to have a go at it. I got some fel-pro umbrella type seals from Kragen nad the air hose adapter that screws into the spark plug hole, and some new spark plugs too. Everything went pretty smoothly. The only problems I had were on 3 of the valves when I used the spring compressor, it pulled up on the spring instad of pushing down. What I'm saying is instead of pushing the spring away from the valve keepers, it pulled it up from the head. The spring "caps" were holding onto the keepers real TIGHT. I tried wiggling the compressor tool while pushing down to break it free and I tried whacking it with the palm of my hand. No dice. I tried just pushing straight down on it, but that just opened the valve up. The keepers were STUCK. So, I got out my lead hamer and gave a relatively light, but sharp tap on the top edge of the spring. Voila! They all came loose with the lead hammer. It was a very light tap. These three valves are the only snag I encountered. After all the seals were replaced, I adjusted the valves as per the factory manual, put the rocker covers back on and fired her up. It sounded like crap. It ran like it was missing on a few cylinders. And there was lots of noise from the coming from the valve covers. I checked the plug wires and the firing order and everything was cool. So the next day I busted out some old valve covers and cut a slot in the top so I could access the valve adjusting nuts while the engine was running. I fired it up and adjusted all the nuts until the rockers were as quiet as I could get them. The engine was now running smoother, but not like it did before I messed with it. What I also noticed while I had the open covers on was that there was VERY little oil coming through the little holes on the rocker arms. on some it looked like no oil flowing at all. Also, after the truck warmed up, it started smoking out of the exhaust, but only from the right side of the engine. I' pretty sure I'm burning coolant cause the smoke is white. But I think I see a bit of a blue tint also. I put my hand in front of the exhaust while it smoked and could feel moisture. I decided to take it around the block and as soonas I put it in drive it started stumbling and stuttering again til I gave it some gas. I didn't like the sound of that so I put it right back in the driveway. So now I have a few ???'s

1. Could the 90 psi I used to hold the valves closed during the install have blown a hole in my head gasket? It doesn't seem likely given that it sees much more than that durnig combustion.

2.Why might I be flowing little to no oil through the pushrods? My oil pressure guage reads about 30 most of the time and it drops to 10-15 sometimes while I am idling.

3.Why does it run somewhat smooth in neutral, but when I put it in drive it starts to run like garbage?

5. I bought fel pro head gasket set, and a new oil pump. This weekend if all else fails I'll pull the heads and replace the gaskets and install the new pump. If I did this, should my problems go away?
One more thing, a few times I turned the air to the cylinder on before I had loosened the rocker arms, thus sending air either back through the intake, or out the exhaust. Sometimes, yes, I am an idiot. Could this have caused any problems?

Almost sounds to me like a majority of your problem is a vacuum leak...what happens when you cover the carb with your hand while it's idling? (you should be able to kill it)

You are going to have some condensation, but you've gotta get the exhaust hot for a fair amount of time before you "burn" it all out of there. A compression test should reveal which cylinder is having problems, but it could be the gasket, rings, piston, or a valve. Never had a bad head gasket, so I don't know that it would feel much different than a large vacuum leak, which I *have* had before. Had a hole in a piston too, but the oil consumption was, um, high. /forums/images/graemlins/smile.gif

Sounds like a few lifters are stuck out. SOmetimes you need to squeeze the oil out of them. The additional 1/2 turn or so after your pushrod starts to snug is to center the lifters. If you have a stuck one it will open the valve. Anyway, valve seal jobs don't work if your guides are roached.

I think you might be right about the lifters. I just did a compression test and got ZERO compression on cyl. #7. How do I go about unsticking any stuck lifters? Do I hafta pull the intake? BTW, the seals I pulled off of it were the o-ring type and some of them were pretty chewed up.

make sure you do the comp test with the rockers adjusted out you may have bent a valve. Also I dont like the way books show adjusting two cylinders valves at the same time only do one at a time. Check both before rebuild.

Welcome to CK5! And thanks for the reply, bro. That post is almost 3 years old. That engine ended up self destructing, I'm running a crate 350 now. FWIW, the smoke was from oil that had found it's way into the exhaust manifold during the swap. It took about a week to burn it all out. I now adjust my rockers with the engine running and some old valve covers where I cut out the top.

Useful Searches

>
About Us>
>
In May of 1999 CK5 started out as a tribute to America's favorite 4x4 utility truck. Since then it has grown to be
a leader among full size Chevrolet K5 Blazer and GMC Jimmy web sites across the Internet. CK5 has since expanded
to include the C/K series GM Truck and Suburban as well as past and present GM models.
>>
With its technical articles, factory specifications, photo gallery, classifieds, active message forum, product
reviews and original automotive content it's an unbeatable source.